Improvement in lifting-jacks



R. T. SMART & R. T. SMART, Jr.

Improvement in Lifting-Jacks.

N0. 126,496 Patented May 7,1872.

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ROBERT T. SMART AND ROBERT T. SMART, JR, OF TROY, NEW YORK.

IMPROVEMENT IN LlFTlNG-JACKS.

Specification forming part of Letters Patent No. 126,496, dated May 7,1872.

Specification describing a new andImproved Lifting-Jack, invented byROBERT T. SMART and ROBERT T. SMART, Jr., of Troy, in the county ofRensselaer and State of New York.

This invention consists of a short lifting-bar pivoted at one end to theupper ends of links, in the lower ends of which a lever is pivoted toact on the under side of said lifting-bar for swinging up the free end,which is placed under the'weight to be lifted, the whole being arrangedin a vertical slot of a stand, and suspended by the ends of thepivot-pin of the lifting-bar. The lower ends of the links are preventedfrom swinging by the action of the resistance on the lifting-bar and thelever. The under side of the lifting-bar has a notch, into which the endof the lever locks self-actingly, to hold the weight up after it israised. The lifting apparatus is shifted higher or lower on the stand byplacing the suspending-pivot in any one of a series of notches in thestand, one above another, for that purpose.

Figure 1 is a sectional elevation of our improved lifting-jack, and Fig.2 is a front elevation.

Similar letters of reference indicate corresponding parts.

A is a stand, of any suitable kind, with a long vertical slot, B, in theupper part, and a series of transverse notches, O, in one side crossingthe slot. D is the aforesaid liftingbar, having one end fitted to workfreely in the slot, and connected by a pivot-pin, E, with a pair oflinks, F, one on each side, said pin projecting at each end beyond thelinks to lie in the notches O, as clearly shown. These links extenddownward in the slot, and through to the other side, and have the leverG, suspended in the lower ends by a pin, H, projecting at the ends tobear against the side of the stand opposite the one having the notchesG, to hold the lever against being forced back by the weight. The shortarm I of said lever curves upward slightly, and is rounded and shod witha metal strap or plate, as shown, to act against the lower side of thelifting-bar, which lies upon it, for raising it up after the loadsay theaxle of a wag0nhas been taken on the plate J, and force it upward. Saidlifting-bar has a notch, K, in the under side, into which the end I ofthe lever comes when the load has been lifted high enough, and by whichthe said lever is locked self-actingly, to sustain the load withoutother fastenings, but so as not to prevent being unlocked ordisconnected readily when the load is to be let down again by theraising of the long arm of the lever.

The lifting-bar and lever are readily adjusted to the height of the axleor other load to be lifted by shifting the pin E to the differentnotches.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent- 1. The combination of the lifting-bar D, lever I, and connecting-links F with a stand, A, the same being arrangedfor fastening or locking to support the weight, and to be unfastened bythe lever, all substantially as specified.

2. The said lifting-bar, lever, and links, connected by the pins E and Hprojecting laterally on the sides of the stand A, and arranged to beadjusted in the slot of the same, as shown and described.

ROBT. T. SMART. ROBT. T. SMART, JR. Witnesses:

D. W. FORD, W. GUY.

